At the same time he started singing as Gentle Bones, he was also into post-hardcore bands such as American quartet Emarosa.
Through local music forum Soft, Tan found out that a newly formed local band interested in the same kind of music he was, Andrew Saint, were looking for a singer. He went for an audition and was accepted on the spot.
From 2010, Tan fronted the band at several gigs at venues such as *SCAPE. In 2011, they auditioned for a slot on annual music festival Baybeats' budding band programme but did not get it.
Due to the nature of the band's music, he had to adopt a markedly different singing style, one that involved a lot more shouting and screaming. It was not his strongest suit, he admits.
"I wasn't a very strong vocalist and I realised over time that my voice couldn't stand above a heavy band," he says. "I was screaming my lungs out, shouting so loudly and trying to hit notes. But my time with Andrew Saint helped me with my range and forced my vocal chords to stretch out a bit more."
More importantly, he credits his bandmates for opening his eyes to a more comprehensive overview of making music. "They were sort of my guide in this music journey. They taught me about the idea of creating, recording, putting out music and marketing it."
In 2013, he left the band to concentrate on his solo music, which by then had included two early singles, Waking Up, released in 2011 and Here's A Letter, released in 2012. Andrew Saint had also become less active after the bandmates enlisted in national service.
They are still close friends. The band evolved to become alternative rock trio Heir Of Hounds and their debut single, released in March this year, features Tan on guest vocals.
Soon after he left the band, he spent a year building up his audience, mostly through music videos on YouTube. To him, the moving visuals that accompany his songs are as important as the music. His first professionally made music video, for the song Until We Die from his eponymous debut EP, has been viewed more than 700,000 times on YouTube.
One of his proudest achievements is having produced a music video for every single song off the EP. "I'm from the MTV generation. I view music as the entire product, from the videos down to the music, the actual songs," he says.
In late 2013 and early 2014, Until We Die and another single, Save Me, went to the top of the local iTunes singles chart. Based on pre-orders alone, the full EP that the two songs were taken from went to No. 1 on the local iTunes album chart when it was released in August 2014.
He was also playing major gigs, including the Esplanade's Mosaic Music Festival in 2012, the SG50 countdown at The Float @ Marina Bay in front of a 25,000-strong audience, opening slots for American acts Christina Perri and Us The Duo at their gigs here, as well as performances in London, part of a series of shows organised by The Music Society, Singapore and the Singapore Tourism Board.
Tan also performed and wrote songs for events such as the SEA Games last year, and contributed a tune, Sixty Five, for the soundtrack of 1965, the local film based on Singapore's independence released last year. He has also collaborated with other Singapore artists such as DJ-Producer MMXJ.
It was also last year that his rise in the local music scene almost ground to a halt. He was detained by Indonesian authorities in Jakarta from September to December.
Tan was in the Indonesian city to perform with American singer- songwriter Kina Grannis. After their show at Komunitas Salihara, a concert venue in Jakarta, immigration officials took their passports and told them that they did not have performance permits.
The show promoters had apparently failed to secure them.
Tan, Grannis and 12 other musicians and crew were forced to cancel the rest of their regional tour, Tan's first overseas one. It would have included shows in Hong Kong, Kuala Lumpur and Manila.
To his dismay, he had to cancel his original Esplanade Concert Hall date on Dec 10, a show that had sold out within a month.
Tan and the others stayed in hotels, had visits from friends and family and were free to roam the city.
The experience was the lowest point in his music journey, he says.
"It was a struggle to be there for 99 days. Every week, you were told that you were going to leave the next week," he says. "But I don't regret it, it helped me consolidate my thoughts about how I wanted to approach the new music."
He and the crew coped by trying to work on music as much as they could, communicating with their collaborators online. More importantly, his time there gave him a renewed drive to succeed.
"It gave me motivation to try to make this music thing work and to be able to be significant enough that the promoter will sort out your permits for you."
The group was allowed to leave on Dec 22, after a court hearing in which Universal Music Singapore paid a fine of $5,000 for Tan and his entourage of four. The concert promoters were fined.
To his close friends, his rising popularity has not changed him.
"Joel is the best person to chill with and have spontaneous fun," says Sara Pang, 22, a Singapore Management University student and close friend, who has known him since 2010.
"He's generous and relatable. As a friend, it's heartwarming to see him experience the success he has today and still remain the Joel Tan I knew from years ago."
The singer is in a relationship, but declines to say who he is dating. He lives with his parents and two siblings in a condominium in Bukit Timah. His brother, 21, and sister, 19, are waiting to enter university and study law. Their father is a lawyer.
Despite not following in his footsteps, Tan says that his father plays a big role in his life choices.
"My dad is a huge influence on me, he always gives me direction for how I should approach an idea. He understands what I'm trying to do with Gentle Bones. I always talk to him about the business and branding approach that I have to music. He's the one who encourages me to have longer-term plans."
The older Mr Tan, 53, who declined to give his full name, says that his son has always been resourceful.
He says: "Joel has always been independent in his thoughts and the ways he goes about things. He appears nonchalant and shies away from competition, but has a keen and intense ambition to succeed in his music."
His 51-year-old mother, a retired accountant, helps out with his finances.
Tan would not reveal how much he makes, but will only say that his income from live performances, royalties, sponsorships and songwriting fees allows him to live comfortably. It is also enough for him to pay his university fees, which amounts to about $8,000 a year.
Due to his music work, he has a special arrangement with his university and needs to attend school about 1½ days a week. He chose business studies because he feels it will be useful in his career.
"Technically, I am running my own business," he says.
His time in Jakarta, during which he missed a semester of school, has made him re-think his pursuit of a degree.
"Speaking honestly, if this music thing were to ever work out, I would not be able to finish my degree and I'm willing to forego it."
His plans to tour the region to promote the release of his new EP might clash with his classes. He says that he is still thinking about whether to take a sabbatical from school or to drop out.
"To break out in the region is something I put a lot of importance on, and if I am able to do that, I would be more than happy to put school off. I want, more than anything, to do this line of work."
MORE: Watch Gentle Bones talk about his craft in ST Sessions, filmed last year.